RECENT HIGH-STRAIN DYNAMIC TESTING EXPERIENCE WITH STEEL PILE PILES WITH CONCRETE PLUGS-Video

Video Transcription

Video Summary

The presentation examines the use of concrete plugs in large-diameter, open-ended steel pipe piles to increase driving resistance and achieve termination before piles reach rock. Plugs create a substantial, uncertain impedance contrast that can overwhelm high-strain dynamic test signals and make signal matching difficult.<br /><br />In a case study, piles were tested before and after plugs were installed. Stacking multiple blows helped assess signal quality and compare responses. Rather than matching the plugged-pile signals directly, the presenters matched an adjacent open-ended pile first, then carried its soil-resistance parameters over to the plugged pile. This produced a more credible match and indicated increased toe resistance.<br /><br />The presenters recommend keeping plugs short (generally an L/D ratio of at least 5), placing them near the pile toe, and maintaining accurate records of plug length, concrete quantity, and strength. Pre- and post-plug testing on comparable piles can improve analysis. They also stress accounting for plug effects in drivability analyses and call for further research and load testing.

Keywords

concrete plugs

steel pipe piles

driving resistance

high-strain dynamic testing

signal matching

toe resistance